Memoization in Kotlin

memoize.kt

fun <A, R> memoize(function: (A) -> R): (A) -> R {
	val results = mutableMapOf<A, R>()
	return { arg -> results[arg] ?: function(arg).also { results[arg] = it } }
}

fun fib(n: Long): Long = if (n < 2) n else cfib(n - 1) + cfib(n - 2)

val cfib = memoize(::fib)

fun main() {
	(1..50L).forEach { println(cfib(it)) }
}